Palaeogeographic Reconstruction of the Central Altyn Tagh Within Rodinia: Evidence From Detrital Zircon U‒Pb Geochronology and Hf Isotopes in the South Washixia Area, NW, China

ABSTRACT The Altyn Tagh region preserves extensive Precambrian terranes, but poor exposure and limited high‐precision geochronological and isotopic data have hindered reconstruction of its Meso–Neoproterozoic tectonic affinity within Rodinia. This study presents new detrital zircon U‒Pb geochronological, in situ Hf isotopic and provenance data from the Mesoproterozoic Taxidaban Group and the Neoproterozoic Suoerkuli Group in the Central Altyn Tagh. The Taxidaban Group is characterised by zircon ages mainly between 1.2 and 1.8 Ga, with a dominant peak ca. 1.4 Ga, and its youngest zircon populations constrain a maximum depositional age of 1150–945 Ma. The Suoerkuli Group shows a broadly similar age spectrum and, together with an age of ca. 930 Ma for volcanic rocks at its base, constrains deposition to approximately 930–896 Ma. Lithological associations suggest deposition in a marine to volcano–sedimentary basin setting. Mesoproterozoic detrital zircons are dominated by positive ε Hf ( t ) values but also include negative values, suggesting a complex source region involving both relatively juvenile crust and reworked older crust. The detrital zircon age spectra and Hf isotopic characteristics differ from those of the Tarim, North China and Yangtze cratons, but are broadly comparable to those of Laurentia, Baltica and Amazonia, supporting possible palaeogeographic affinity with the Laurentia–Baltica–Amazonia system.